Tuesday, November 29, 2016

AC130F1 and Fountek horn loaded ribbon bookshelf

This little bookshelf started by looking at excellent fr response of Aurum Cantus 5" midbass AC130F1. Originally I wanted to pair it with small Dayton dome tweeter, but sound was lacking something. Fountek true ribbon in its horn loaded offering has excellent spec and sounds great. These two are meant to work together. I used rather simple crossover, first order series crossover, with just one cap and one inductor, at 7kHz. I selected this crossover frequency to suppress small breakup bump on midbass. Plus ribbons like to be crossed high. I added baffle step later, to compensate for rising response. Just one inductor in parallel with resistor.
Below are some pics from setup with mini dsp crossed at ~150 Hz to subwoofer. You can see how well the little speaker measures, almost ruler flat, this is in room response. First response is just the bookshelf alone, second one is with the sub. Off axis behaviour is exceptional.

Thursday, November 17, 2016

FM radio stations near Washington DC

Frequency                 Name                         Comment

88.1                           ?                                 latino
88.5                          WAMU
89.3                           ?                                 jazz
90.1                           WCSP                        mono, politics...
90.9                           WETA                       classical music, great
91.3                            ?
91.5                            ?                                classical from Baltimore
91.9                            ?                                christian
92.3                            ?                                crap
92.5                            WINC FM               
93.1                            ?                                country
93.3                            ?                                country
93.9                            ?                                crap
94.3                            ?
94.7                            ?                                rock
95.5                            WPGC                      crap
96.3                            WHUR
96.7                            ?
97.1                            WASH
97.5                            ?
97.9                            ?
98.3                            ?
98.7                            WMZQ                     country
99.1                            Bloomberg
99.3                            ?
99.5                            HOT99.5
99.9                            WFRE Frederick      country
100.3                          BIG100.3                  rock
101.1                          DC101                      idiot in the morning
101.5                          ?
102.3                          ?
102.7                          ?
103.5                          WTOP
103.9                          ?
104.1                          ?
104.7                          ?                               country
105.1                          ?                               christian
105.9                          WMAL
106.7                          The FAN106.7
107.3                          ?                               rock
107.7                          ?
107.9                          ?                               latino         

Saturday, May 21, 2016

3 domes monitor

I am very fond of dome speakers, as they often show clean waterfall. The sign of much less resonances as cone speakers. They do sound good too. Dome tweeters has been around for decades, dome midrange drivers were used less often, but they are nothing new. In spite of Lynn Olson badmouthing dome mids, large amount of speaker makers produced great sounding speakers using dome midrange drivers. Here is my effort at making small 3-way three domes based mini monitor. As I have limited woodworking possibilities since I moved to apartment, I used Ikea bookshelf to ease the building. The result is great sounding, ok looking bookshelf speaker. I used 3/4" dayton dome tweeter, 2" dayton aluminium dome, to which I removed the front plate to make it closed mounted to tweeter, and 5" peerless woofer. Here are few pics.

Granted, it does not go very deep, it has only 5" woofer, but as bookshelf speaker, this is enough. Once used as satelite speaker with subwoofer, this is seriously good sounding speaker, as you can see how flat it measures.

Long time ago I built this little bookshelf speaker based on Philips tweeter and midrange, both domes. Woofers in this case are 6" daytons in clam isobaric configuration. This system is used with subwoofer and sounds great.

Sunday, March 13, 2016

System 2

System two consists of yet another SONY tuner ST-S555ES, then Cambridge Audio Azur CD player 640C, Phillips DCC digital tape player, Pioneer RT-707 reel to reel player with type II dolby and diy turntable based on TESLA 1100 arm and AKAI direct drive table. Phono preamp is either SPARTA or Actidamp MkII. Cartridges include Benz Micro ACE, Audio Technica ATOC9, AT ML440a microline, Ortofon Red, AT92E, Signet and many others.
Signal selector is diy, preamp is JC-2 in old Parasound preamp box, Behringer Ultra Curve 31 band digital equalizer, and two LM1875 chip amplifiers, one in transconductance config to power mid/tweet section, one stock to power woofers. Active crossover ~160 Hz for woofer section. Like first system, this one is biamplied too.
Speakers are diy, based on HiVi ribbon tweeter, Dayton 2" soft dome, two Dayton 6" midbass in isobaric clamp, and 15" Jamo as woofers in closed boxes.   

Tuesday, March 8, 2016

I am back!

Hi friends,

it's been a while....I have not posted anything on my blog in two years. It does not mean I stopped listening to music or building speakers and amplifiers. I was on sabbatical. Well, I used to work for small biotech company, which was acquired by large biotech company (swallowed, forcefully bought, insert your own...), and as it often happens, things change. Some people were let go, some were kept. I was offered to relocate into neighboring state, or take severance. I opted for severance. I got rid of most of my furniture, and gave away a lots of my audio stuff, kept just the best and moved my stuff into friends one-bedroom basement. Then I went on tour around the Australia and New Zealand. On the way back I stopped in Singapore and Dubai, and went for few month to good old Europe to visit relatives. Then I visited Banff in Canada. All together about nine months. Since then, I found another job in small  biotech company and moved to 2 bedroom apartment in Germantown. I consolidated my two main systems into living room, so now I have two systems intertwined in one room. Here is how it looks.
System one...

My audio system currently consists of Jungson HDCD player Moon Harbor, SONY ST-555ES tuner, Onkyo 2700 cassette player, Technics DCC deck, Technics SL1200 turntable, Onkyo 306RS riaa preamp (only for turntable), diy signal selector, modified 6H6P tube preamp, Behringer UltraCurve 31 digital equalizer, LM1875 transconductance amp, 160 Hz active crossover for subwoofer, and 100 watt amp for woofers. Speakers are diy, all open baffle, tweeter is B&G neo3 with back plate removed, upper mid is Fostex FF125K, lower midbass is 6" Pioneer, woofers are two 15" Jamo per channel in dipole configuration. Sounds ok for now.
Maybe future project will be mini dsp 2x8 with four channel amplification. Who knows.